Axial gap dual permanent magnet generator

Abstract

A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential in accordance with the invention includes a plurality of permanent magnet rotors (20 and 22) mounted on a drive shaft (26) with at least one of the rotors being rotatable with respect to the drive shaft to vary an angular position of the at least one of the rotors relative to the shaft to produce a mutual variable magnitude magnetic axial field extending parallel to the drive shaft; at least one stator (26, 28, 72) disposed at a position axially offset from the plurality of rotors which is magnetically coupled to the variable magnitude permanent magnet axially field; and a mechanism (46, 48) responsive to a stator fault for angularly positioning the rotors relative to each other so that the permanent magnetic field coupled to the at least one stator is zero.

We claim: 
     
       1. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a plurality of permanent magnet rotors mounted on a drive shaft with at least one of the rotors being rotatable with respect to the drive shaft to vary an angular position of the at least one of the rotors relative to the shaft to produce a mutual variable magnitude magnetic axial field extending parallel to the drive shaft;   at least one stator disposed at a position axially offset from the plurality of rotors, which is magnetically coupled to the mutual variable magnitude magnetic axial field; and   means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the mutual variable magnitude magnetic axial field coupled to the at least one stator is zero and wherein;   the means for angularly positioning uses the energy stored within the magnetic axial field extending between the plurality of permanent magnet rotors to rotate the rotors to a relative angular position at which the magnetic axial field coupled to the at least one stator is zero in response to a stator fault.   
     
     
       2. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a plurality of permanent magnet rotors mounted on a drive shaft with at least one of the rotors being rotatable with respect to the drive shaft to vary an angular position of the at least one of the rotors relative to the shaft to produce a mutual variable magnitude magnetic axial field extending parallel to the drive shaft;   at least one stator disposed at a position axially offset from the plurality of rotors, which is magnetically coupled to the mutual variable magnitude magnetic axial field; and   self-regulating means, automatically responsive to a stator fault, for angularly positioning the rotors relative to each other so that the mutual variable magnitude magnetic axial field coupled to the at least one stator is zero.   
     
     
       3. A permanent magnet generator in accordance with claim 1 wherein: the means uses energy stored within a torsion spring which is coupled to the drive shaft and the at least one rotor to rotate the rotors to a relative angular position at which the magnetic axial field coupled to the at least one stator is zero in response to a stator fault.   
     
     
       4. A permanent magnet generator in accordance with claim 1 further comprising: first and second permanent magnet rotors mounted on the drive shaft each having spatially opposed first radially extending faces with one of the pair of rotors being rotatable with respect to the drive shaft;   first and second stators which are fixed to prevent rotation with respect to the drive shaft with a first radially extending face of the first stator facing a second radially extending face of the first rotor which is parallel to the first radially extending face of first rotor and a first radially extending face of the second stator facing a second radially extending face of the second rotor which is parallel to the first radially extending face of the second rotor;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during generation of the output potential extends in a loop enclosing spatially opposed non-magnetic material sections of the rotors with the loop passing through spatially opposed sections of the first end second stators and spatially opposed pairs of permanent magnets of the first and second rotors.   
     
     
       5. A permanent magnet generator in accordance with claim 1 further comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having first and second spatially opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first rotor having a radially extending face parallel and opposed to the first face of the stator and the second rotor having a radially extending face parallel and spatially opposed to the second face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in a loop enclosing spatially opposed nonmagnetic material sections of the rotors with the loop passing through adjacent sections of the stator which is fixed and spatially opposed pairs of permanent magnets and a magnetic yoke of the first and second rotors.   
     
     
       6. A permanent magnet generator in accordance with claim 1 further comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having spatially opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first and second rotors having radially extending faces parallel to the radially extending faces of the stator with the faces of the first and second rotors being spatially opposed to only one radially extending face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in a loop enclosing spatially opposed non-magnetic material sections of the rotors with the loop passing through the stator which is fixed and spatially opposed pairs of the permanent magnets and magnetic yoke of the first and second rotors.   
     
     
       7. A permanent magnet generator in accordance with claim 1 further comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having first and second opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first rotor having a radially extending face parallel and opposed to the first face of the stator and the second rotor having a radially extending face parallel and opposed to the second face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in a loop through the magnetically permeable material sections in the first and second rotors, adjacent sections of the stator which is fixed and spatially opposed pairs of permanent magnets.   
     
     
       8. A permanent magnet generator in accordance with claim 1 further comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first and second rotors having radially extending faces parallel to the radially extending faces of the stator with the faces of first and second rotors being spatially opposed to only one radially extending face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in first and second loops, each loop extending through at least one of the first and second rotors, adjacent magnetically permeable material sections of at least one of the first and second rotors, through the stator which is fixed and spatially opposed permanent magnets within one of the first and second rotors.   
     
     
       9. A permanent magnet generator in accordance with claim 1 further comprising: first and second permanent magnet rotors mounted on the drive shaft each having spatially opposed first radially extending faces with one of the pair of rotors being rotatable with respect to the drive shaft;   first and second stators which are fixed to prevent rotation with respect to the drive shaft with a first radially extending face of the first stator facing a second radially extending face of the first rotor which is parallel to the first radially extending face of first rotor and a first radially extending face of the second stator facing a second radially extending face of the second rotor which is parallel to the first radially extending face of the second rotor;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during generation of the output potential extends in a loop through adjacent magnetically permeable material sections of the rotors, a permanent magnet and a section of one of the stators.   
     
     
       10. A permanent magnet generator in accordance with claim 4 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       11. A permanent magnet generator in accordance with claim 5 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       12. A permanent magnet generator in accordance with claim 6 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       13. A permanent magnet generator in accordance with claim 7 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       14. A permanent magnet generator in accordance with claim 8 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       15. A permanent magnet generator in accordance with claim 9 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       16. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: first and second permanent magnet rotors mounted on the drive shaft each having spatially opposed first radially extending faces with one of the pair of rotors being rotatable with respect to the drive shaft;   first and second stators which are fixed to prevent rotation with respect to the drive shift with a first radially extending face of the first stator facing a second radially extending face of the first rotor which is parallel to the first radially extending face of first rotor and a first radially extending face of the second stator facing a second radially extending face of the second rotor which is parallel to the first radially extending face of the second rotor;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during generation of the output potential extends in a loop enclosing spatially opposed non-magnetic material sections of the rotors with the loop passing through spatially opposed sections of the first and second stators and spatially opposed pairs of permanent magnets of the first and second rotors.   
     
     
       17. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having first and second opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first rotor having a radially extending face parallel and spatially opposed to the first face of the stator and the second rotor having a radially extending face parallel and spatially opposed to the second face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in a loop enclosing spatially opposed non-magnetic material sections of the rotors with the loop passing through adjacent sections of the stator which is fixed and spatially opposed pairs of permanent magnets and a magnetic yoke of the first and second rotors.   
     
     
       18. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having spatially opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first and second rotors having radially extending faces parallel to the radially extending faces of the stator with the faces of the first and second rotors being spatially opposed to only one radially extending face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first ad second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending non-magnetizable material sections being disposed between adjacent permanent magnets; and wherein   the variable magnitude magnetic axial field during the generation of the output potential extends in a loop enclosing spatially opposed non-magnetic material sections of the rotors with the loop passing through the stator which is fixed and spatially opposed pairs of the permanent magnets and a magnetic yoke of the first and second rotors.   
     
     
       19. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having first and second spatially opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first rotor having a radially extending face parallel and spatially opposed to the first face of the stator and the second rotor having a radially extending face parallel and spatially opposed to the second face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in a loop through magnetically permeable material sections in the first and second rotors, adjacent sections of the stator which is fixed and spatially opposed pairs of permanent magnets.   
     
     
       20. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: a stator which is fixed to prevent rotation with respect to the drive shaft having opposed radially extending faces;   first and second permanent magnet rotors which are attached to the drive shaft with the first and second rotors having radially extending faces parallel to the radially extending faces of the stator with the faces of first and second rotors being spatially opposed to only one radially extending face of the stator with one of the first and second rotors being rotatable with respect to the drive shaft;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during the generation of the output potential extends in first and second loops, each loop extending through at least one of the first and second rotors, adjacent magnetically permeable material sections of at least one of the first and second rotors, through the stator which is fixed and spatially opposed to permanent magnets within one of the first and second rotors.   
     
     
       21. A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential comprising: first and second permanent magnet rotors mounted on the drive shaft each having spatially opposed first radially extending faces with one of the pair of rotors being rotatable with respect to the drive shaft;   first and second stators which are fixed to prevent rotation with respect to the drive shaft with a first radially extending face of the first stator facing a second radially extending face of the first rotor which is parallel to the first radially extending face of first rotor and a first radially extending face of the second stator facing a second radially extending face of the second rotor which is parallel to the first radially extending face of the second rotor;   a plurality of radially extending permanent magnets mounted in each of the first and second rotors at spaced apart circumferential locations disposed around a circumference of the first and second rotors with radially extending magnetically permeable material sections being disposed between adjacent permanent magnets; and wherein   the mutual variable magnitude magnetic axial field during generation of the output potential extends in a loop through adjacent magnetically permeable material sections of the rotors, a permanent magnet and a section of one of the stators.   
     
     
       22. A permanent magnet generator in accordance with claim 16 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       23. A permanent magnet generator in accordance with claim 17 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       24. A permanent magnet generator in accordance with claim 18 wherein: an axis extending from a north pole to a south pole of the permanent magnets is parallel to the drive shaft.   
     
     
       25. A permanent magnet generator in accordance with claim 19 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       26. A permanent magnet generator in accordance with claim 20 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       27. A permanent magnet generator in accordance with claim 21 wherein: an axis extending from a north pole to a south pole of the permanent magnets is perpendicular to the drive shaft.   
     
     
       28. A permanent magnet generator in accordance with claim 16 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the variable magnitude magnetic axis field coupled to the first and second stators is zero.   
     
     
       29. A permanent magnet generator in accordance with claim 17 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the   
     
     
       30. A permanent magnet generator in accordance with claim 18 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the variable magnitude magnetic axial field coupled to the stator is zero.   
     
     
       31. A permanent magnet generator in accordance with claim 19 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the variable magnitude magnetic axial field coupled to the stator is zero.   
     
     
       32. A permanent magnet generator in accordance with claim 20 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the variable magnitude magnetic axial field coupled to the stator is zero.   
     
     
       33. A permanent magnet generator in accordance with claim 21 further comprising: means, responsive to a stator fault, for angularly positioning the rotors relative to each other so that the variable magnitude magnetic axial field coupled to the first and second stators is zero.